JP2023151205A - Motor and blower with the same - Google Patents

Abstract

To provide a motor which can be miniaturized in an axial direction.SOLUTION: A motor comprises: a rotor; a stator; a circuit board 28; a stator housing part 25; an encapsulation member 26; and a cover part 27. The circuit board is connected with the stator and arranged on one axial side of the stator. The stator housing part houses the stator and the circuit board, has an opening 25a on one end surface in the axial direction and is formed in a cylindrical shape. The encapsulation member is filled in the stator housing part. The cover part covers the opening. The stator has a bearing holding part. The bearing holding part holds a bearing which rotatably supports a shaft extending along a rotational axis inside and is formed in the cylindrical shape. The circuit board has a board through hole 28a arranged on the rotational axis and penetrating in the axial direction. One end part in the axial direction of the bearing holding part is inserted into the board through hole and extends in one side in the axial direction further than the circuit board. In the bearing holding part, an oil repellent layer 2313 is formed on an outer surface in a radial direction on one side in the axial direction further than one end in the axial direction of the circuit board.SELECTED DRAWING: Figure 9

Description

The present invention relates to a motor and a blower device including the motor.

A conventional motor includes a rotor, a stator, a circuit board, a stator housing, and a sealing member (insulator). The rotor rotates around a rotation axis. The stator faces the rotor radially inwardly with a gap therebetween. The circuit board is connected to the stator and placed on one axial side of the stator. The stator accommodating portion accommodates the stator and the circuit board, and has an opening at one end surface in the axial direction. The liquid sealing member is filled into the stator accommodating portion and hardens after a predetermined period of time (see, for example, Patent Document 1).

Patent No. 6280771

However, in conventional motors, the sealing member may bulge and harden along the radial inner surface of the stator housing portion, and a fillet may be formed at the radially outer end of the sealing member. When the fillet is formed, there is a possibility that the cover covering the opening of the stator accommodating portion comes into contact with the fillet, causing the motor to become larger in the axial direction.

An object of the present invention is to provide a motor that can be made smaller in the axial direction.

An exemplary motor of the present invention includes a rotor, a stator, a circuit board, a stator housing, a sealing member, and a lid. The rotor rotates around a rotation axis. The stator faces the rotor radially inwardly with a gap therebetween. The circuit board is connected to the stator and placed on one axial side of the stator. The stator accommodating portion accommodates the stator and the circuit board, has an opening at one end surface in the axial direction, and is formed in a cylindrical shape. The sealing member is filled into the stator housing, and the lid covers the opening. The stator has a bearing holding part. The bearing holding part holds therein a bearing that rotatably supports a shaft extending along the rotation axis, and is formed in a cylindrical shape. The circuit board is disposed on the rotating shaft and has a board through-hole that passes through the circuit board in the axial direction. One axial end of the bearing holding portion is inserted into the board through-hole and extends to one axial side of the circuit board. The bearing holding portion has an oil-repellent layer formed on its radial outer surface on one axial side of the circuit board from one axial end thereof.

An exemplary motor of the present invention includes a rotor, a stator, a circuit board, a stator housing, a sealing member, and a lid. The rotor rotates around a rotation axis. The stator faces the rotor radially inwardly with a gap therebetween. The circuit board is connected to the stator and arranged on one axial side of the stator. The stator accommodating portion accommodates the stator and the circuit board, has an opening at one end surface in the axial direction, and is formed in a cylindrical shape. The sealing member is filled into the stator housing, and the lid covers the opening. The stator has a bearing holding part. The bearing holding part holds therein a bearing that rotatably supports a shaft extending along the rotation axis, and is formed in a cylindrical shape. The circuit board is disposed on the rotating shaft and has a board through-hole that passes through the circuit board in the axial direction. One axial end of the bearing holding portion is inserted into the board through-hole and extends to one axial side of the circuit board. The bearing holding part has a holding protrusion. The holding protrusion is disposed on one axial side of the circuit board, protrudes radially outward from the radial outer surface, and has an annular shape.

According to the exemplary embodiment of the present invention, it is possible to provide a motor that can be made smaller in the axial direction.

FIG. 1 is a perspective view of a blower device according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the air blower according to the first embodiment of the present invention. FIG. 3 is a vertical cross-sectional perspective view of the air blower according to the first embodiment of the present invention. FIG. 4 is an enlarged vertical cross-sectional perspective view of a part of the air blower according to the first embodiment of the present invention. FIG. 5 is a perspective view of the motor according to the first embodiment of the invention. FIG. 6 is a top view of the motor according to the first embodiment of the invention. FIG. 7 is a vertical cross-sectional perspective view of the stator accommodating portion of the motor according to the first embodiment of the present invention. FIG. 8 is a longitudinal sectional view schematically showing a part of the motor according to the first embodiment of the present invention. FIG. 9 is a longitudinal sectional view schematically showing a part of a motor according to a second embodiment of the present invention. FIG. 10 is a vertical cross-sectional view schematically showing a part of a motor according to a third embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In this document, the direction in which the rotation axis J of the blower 1 extends is simply referred to as the "axial direction," and the direction that is centered around the rotation axis J of the blower 1 and perpendicular to the rotation axis J is simply referred to as the "radial direction." The direction along the arc centered on the rotation axis J of 1 is simply referred to as the "circumferential direction." Further, a cross section parallel to the axial direction is called a "longitudinal cross section." Furthermore, "parallel" does not mean parallel in a strict sense, but includes substantially parallel.

Further, for convenience of explanation, the shape and positional relationship of each part will be described with the axial direction as the vertical direction and the vertical direction in FIG. 1 as the vertical direction of the blower device 1. For example, one axial side is defined as the upper side or upper side in the axial direction. The other side in the axial direction is the lower side in the axial direction, or the lower side. Further, one end in the axial direction is defined as an upper end, and the other end in the axial direction is defined as a lower end. Further, one axial end surface is an upper end surface, and the other axial end surface is a lower end surface. In the blower device 1, the "upper side" is the "intake side", and the "lower side" is the "exhaust side". Note that this definition of the vertical direction does not limit the orientation and positional relationship of the blower device 1 when it is used.

<First embodiment>
<1. Overall configuration of the blower>
1 and 2 are a perspective view and an exploded perspective view of an example of a blower device 1 according to a first embodiment of the present invention. The blower 1 includes a motor 20, an impeller 30, and a housing 40.

The impeller 30 is fixed to the motor 20 and rotates around the rotation axis J, and generates an airflow along the rotation axis J toward the axially lower side (the other axial side) X1.

The housing 40 is formed into a cylindrical shape extending along the rotation axis J, and has an air passage 41 that is open at both end faces in the axial direction and allows air flow to flow therein. The motor 20 and the impeller 30 are housed inside the housing 40 . The housing 40 has an exhaust port 42 on the lower end surface (the other end surface in the axial direction) (see FIG. 3), and has an intake port 43 on the upper end side (one end surface in the axial direction).

<2. Housing configuration>
The housing 40 is configured by connecting an upper housing part 40a and a lower housing part 40b in the axial direction. The upper housing part 40a and the lower housing part 40b are resin molded products. In this embodiment, the housing 40 can be divided into an upper housing part 40a and a lower housing part 40b, but the upper housing part 40a and the lower housing part 40b may be formed integrally. The upper housing part 40a has an upper body part 401a, a fixing part 402a, and connecting parts 403a and 403b. The upper body portion 401a extends in the axial direction and is formed into a cylindrical shape.

The fixing portion 402a and the connecting portions 403a and 403b constitute a lid portion 27 that covers an opening 25a (see FIG. 4) of the stator accommodating portion 25, which will be described later. The lid part 27 is a part of the housing 40 and also a part of the motor 20. The fixing portion 402a is disposed on the axially upper side (one axial side) X2 of the stator accommodating portion 25, which will be described later, and has a disk shape that extends radially around the rotation axis J. A stator 23 of the motor 20, which will be described later, is fixed to the fixed portion 402a. That is, the fixed portion 402a is formed into a plate shape to which the stator 23 is fixed.

The connecting portions 403a and 403b extend radially outward from the fixed portion 402a and connect the fixed portion 402a and the housing body portion 40c. A plurality of connecting portions 403a are arranged in the circumferential direction, and are axially opposed to a housing recess 252a, which will be described later. The connecting portion 403b is arranged at one location in the circumferential direction and faces a pullout piece 2522, which will be described later, in the axial direction. Air flowing through the ventilation flow path 41 passes between adjacent connecting portions 403a and 403b.

Further, the connecting portion 403a is formed to be inclined toward one side in the circumferential direction from the radially inner end toward the radially outer side. Thereby, the airflow flowing into the housing 40 from the intake port 43 smoothly flows along the connecting portion 403a. Therefore, the air blowing efficiency of the air blower 1 can be further improved. Note that the connecting portion 403a may be formed to be inclined toward the other side in the circumferential direction from the radially inner end toward the radially outer side. Further, the connecting portion 403a may be formed to extend linearly in the radial direction. The connecting portion 403b is formed to extend linearly in the radial direction.

The connecting portion 403a has a connecting recess 405a (see FIG. 4). The connecting recess 405a is disposed axially facing the stator accommodating portion 25, and is recessed toward one axial side from the lower end surface (the other axial end surface) of the connecting portion 403a. This can prevent the stator accommodating portion 25 from coming into contact with the connecting portion 403 when it swings in the axial direction.

The lower housing portion 40b has a lower body portion 401b that extends in the axial direction and is formed into a cylindrical shape. The lower body part 401b and the upper body part 401a are connected in the axial direction to form a housing body part 40c. That is, the blower device 1 includes a housing body 40c, which extends along the rotation axis J and is formed into a cylindrical shape, with both axial end faces open to form a blowing passage 40a therein. have The motor 20 and the impeller 30 are housed inside the housing body 40c.

<3. Impeller configuration>
The impeller 30 has an impeller cup 31 and a plurality of blades 32. The impeller cup 31 is fixed to the radially outer side of a rotor 24 of the motor 20, which will be described later. The plurality of blades 32 are arranged in the circumferential direction on the radially outer surface of the impeller cup 31.

<4. Motor configuration>
FIG. 3 is a vertical cross-sectional perspective view of the air blower 1, and FIG. 4 is a vertical cross-sectional perspective view showing a part of the air blower 1 in an enlarged manner. The motor 20 includes a shaft 21, a bearing 22, a stator 23, a rotor 24, a stator accommodating portion 25, a sealing member 26, the above-mentioned lid portion 27, and a circuit board 28.

The shaft 21 extends along the rotation axis J. The shaft 21 is a columnar member that is made of metal such as stainless steel and extends in the axial direction.

The bearings 22 are arranged as a pair and spaced apart at least in the axial direction. The bearing 22 is composed of, for example, a ball bearing, but may also be composed of a sleeve bearing or the like. The pair of bearings 22 supports the shaft 21 so as to be rotatable around the rotation axis J relative to the stator 23.

The stator 23 faces the rotor 24 radially inwardly with a gap therebetween. The stator 23 includes a bearing holding portion 231 , a stator core 232 , an insulator 233 , and a coil 234 . The bearing holding part 231 is formed in a cylindrical shape and holds the bearing 22 therein.

The upper end portion (one axial end portion) of the bearing holding portion 231 is fitted into the fitting hole 404a of the fixed portion 402a via the connector 45. Thereby, the bearing holding part 231 is fixed to the fixed part 402a, and the stator 23 and the housing 40 are fixed. The fitting hole 404a is formed to penetrate the fixing part 402a in the axial direction. The connector 45 is formed in an annular shape and is arranged on the inner peripheral surface of the fitting hole 404a. In the connector 45, a bearing holding portion 231 is arranged on the inner circumferential surface. Further, a lower end portion (the other end in the axial direction) of the bearing holding portion 231 is fixed to a stator accommodating portion 25, which will be described later. Note that the connector 45 may be omitted and the upper end (one axial end) of the bearing holding portion 231 may be directly fitted into the fitting hole 404a.

The stator core 232 is configured by vertically stacking electromagnetic steel plates such as silicon steel plates, for example. The insulator 233 is made of insulating resin. Stator core 232 includes an annular core back (not shown) and a plurality of teeth (not shown) that protrude radially outward from the core back and are arranged in the circumferential direction. The Schlater 233 is provided on a portion of the axial outer surface and a portion of the circumferential outer surface of the teeth. Insulator 233 is provided surrounding the outer surface of stator core 232 . Coil 234 is composed of a conductive wire wound around stator core 232 via insulator 233 .

The rotor 24 rotates about the rotation axis J relative to the stator 23. The rotor 24 includes a rotor yoke 241 and a magnet 242.

The rotor yoke 241 is a substantially cylindrical member that is made of a magnetic material and has a lid on the inside in the axial direction. The rotor yoke 241 is fixed to the lower end of the shaft 21 (the other end in the axial direction). The magnet 242 has a cylindrical shape and is fixed to the inner peripheral surface of the rotor yoke 241. Thereby, the magnet 242 is arranged on the radially outer side of the stator 23.

The circuit board 28 contacts the upper end (one end in the axial direction) of the insulator 233 and is disposed between the stator core 232 and the lid portion 27 . The circuit board 28 is, for example, in the shape of a disk that extends radially around the rotation axis J. The circuit board 28 has a board through hole 28a. The substrate through hole 28a is arranged on the rotation axis J and penetrates in the axial direction. The upper end portion (one axial end portion) of the bearing holding portion 231 is inserted into the board through hole 28a and extends axially above (one axial side) X2 than the circuit board 28.

A conductive wire (not shown) constituting the coil 234 is electrically connected to the circuit board 28 . An electronic circuit for supplying drive current to the coil 234 is mounted on the circuit board 28 . Further, the circuit board 28 is connected to a lead wire 50 (see FIGS. 6 and 7), and the lead wire 50 is drawn out of the stator accommodating portion 25 and connected to an external power source. The lead wire 50 is electrically connected to the coil 234, and the lead wire 50 and the stator 23 are electrically connected. In this embodiment, three lead wires 50 are drawn out of the stator accommodating portion 25.

<5. Configuration of stator housing>
5 and 6 are a perspective view and a top view of the motor 20, and FIG. 7 is a vertical cross-sectional perspective view of the stator housing portion 25. In addition, in FIGS. 5 and 6, the rotor 24, the sealing member 26, and the lid part 27 are not shown, and the elastic member 29 is shown by a dotted line. Further, in FIG. 5, the lead wire 50 is not shown, and in FIGS. 6 and 7, the lead wire 50 is shown by a chain line.

The stator accommodating portion 25 is formed in a cylindrical shape and has an opening 25a on one end surface in the axial direction (one end surface in the axial direction). The stator accommodating portion 25 accommodates the shaft 21, the bearing 22, the stator 23, and the circuit board 28 therein. A sealing member 26 is filled in the stator housing portion 25 (see FIG. 4). Thereby, the shaft 21, the bearing 22, the stator 23, and the circuit board 28 are integrated, and the workability of assembling the motor 20 is improved.

A stator core 232 is press-fitted into the inner circumferential surface of the stator accommodating portion 25 . At this time, the radially outer surface of the teeth (not shown) comes into contact with the inner circumferential surface of the stator accommodating portion 25. Further, the outer circumferential surface of the stator accommodating portion 25 faces the magnet 242 in the radial direction via a gap (see FIG. 3).

The sealing member 26 is formed of a hardening type insulating resin or the like, and for example, epoxy resin, silicone rubber, polyurethane resin, or the like is used. The liquid sealing member 26 is filled into the stator accommodating portion 25 through the opening 25a, and hardens after a predetermined period of time. Thereby, the stator 23 and the circuit board 28 are covered with the hardened sealing member 26, and the waterproof and oil-proof properties of the stator 23 and the circuit board 28 are improved.

The stator housing section 25 includes a stator tube section 251, a substrate tube section 252, an intermediate tube section 253, an accommodation lid section 254, and an accommodation slope section 255.

The stator cylinder portion 251 surrounds the stator 23 from the outside in the radial direction. The board cylinder portion 252 surrounds the circuit board 28 from the outside in the radial direction. The intermediate cylindrical portion 253 connects the stator cylindrical portion 251 and the substrate cylindrical portion 252.

The housing lid portion 254 covers the stator 23 from the lower side in the axial direction (the other side in the axial direction) X1, and extends in the radial direction. The accommodation lid part 254 has an accommodation through hole 254a that penetrates in the axial direction and an accommodation holding part 254b. The lower end (the other end in the axial direction) of the bearing holding portion 231 is fitted into the accommodation through hole 254a (see FIG. 3). Thereby, the stator accommodating portion 25 is fixed to the bearing holding portion 231. Further, the accommodation holding portion 254b is formed in a cylindrical shape and protrudes upward in the axial direction (one side in the axial direction) X2 from the periphery of the accommodation through hole 254a. The accommodation holding part 254b holds the lower end (the other end in the axial direction) of the bearing holding part 231.

The substrate cylinder portion 252 has a housing recess 252a. The housing recess 252a is arranged at the upper end (one end in the axial direction) of the stator housing 25, and is recessed from the radially inner surface to the radially outer side. In the radial direction, a gap S is formed between the radially outer edge of the circuit board 28 and the accommodation recess 252a. In the present embodiment, the housing recesses 252a are formed in a portion of the substrate cylinder portion 252 in a convex shape outward in the radial direction, and are provided in three locations at equal intervals in the circumferential direction. Note that the number of accommodation recesses 252a is not limited to three. By providing the housing recess 252a, the sealing member 26 can smoothly flow into the stator housing portion 25 from the gap S. This improves the ease of assembling the blower device 1.

When viewed from the axial direction, at least a portion of the accommodation recess 252a overlaps the connecting portion 403a of the lid portion 27 (see FIG. 4). In this embodiment, the circumferential width of the accommodation recess 252a is less than or equal to the circumferential width of the connecting part 403a, and the entire accommodation recess 252a overlaps the connecting part 403a when viewed from the axial direction. Thereby, the airflow flowing into the housing 40 through the adjacent connecting portions 403a can be prevented from being disturbed in the vicinity of the accommodation recess 252a. Therefore, the air blowing efficiency of the air blower 1 can be improved.

Further, the amount of radial protrusion of the accommodation recess 252a is equal to or less than 1/2 of the radial size of the connecting portion 403a. Thereby, it is possible to further reduce the disturbance of the airflow flowing into the housing 40 through the adjacent connecting portions 403a in the vicinity of the accommodation recess 252a. Note that the amount of radial protrusion of the accommodation recess 252a is preferably smaller as long as the gap S is maintained at a predetermined size.

The intermediate cylindrical portion 253 is inclined radially inward toward the axial lower side (the other axial side) X1. Thereby, the sealing member 26 can be smoothly flowed into the stator cylinder part 251 from the substrate cylinder part 252 along the intermediate cylinder part 253. Moreover, the amount of resin in the sealing member 26 can be reduced, and manufacturing costs can be reduced.

The accommodating inclined portion 255 connects the stator cylinder portion 251 and the accommodating lid portion 254, and is inclined radially inward toward the axially lower side (the other axial side) X1. Thereby, the sealing member 26 can be smoothly flowed into the radially inner side of the accommodation lid part 254 from the stator cylinder part 251 along the accommodation slope part 255.

Further, the stator housing portion 25 has a housing protrusion 251a that projects from the inner surface in the radial direction and extends in the axial direction (see FIG. 7). In this embodiment, the housing protrusion 251a is arranged on the radially inner surface of the stator cylinder section 251. The housing protrusion 251a fits into a groove (not shown) formed on the radially outer surface of the stator core 232 and extending in the axial direction. Thereby, it is possible to easily position the stator core 232 in the circumferential direction within the stator accommodating portion 25. Note that when the stator core 232 is accommodated in the stator accommodating portion 25, the accommodating protrusion 251a is press-fitted between circumferentially adjacent teeth (not shown).

<6. Configuration of cutout>
The stator accommodating portion 25 further includes a notch 2521 and a pull-out piece 2522.

The notch 2521 is recessed from the upper end (one end in the axial direction) of the stator accommodating portion 25 to the lower side in the axial direction (the other side in the axial direction) X1, and the lead wire 50 is drawn out to the outside in the radial direction (see FIG. 7).

The pull-out piece 2522 projects radially outward from the bottom of the notch 2521 and is formed in a plate shape. A rectangular parallelepiped-shaped elastic member 29 is arranged on the upper surface (one end surface in the axial direction) of the pull-out piece 2522. A lead wire 50 is arranged on the upper surface (one end surface in the axial direction) of the elastic member 29 . The upper end (one axial end) of the elastic member 29 is arranged above the upper end (one axial end) of the substrate tube portion 252 in the axial direction (one axial end) X2.

As a result, even if the sealing member 26 before hardening flows out of the notch 2521, it is blocked by the elastic member 29. Therefore, the sealing member 26 before being hardened can be prevented from flowing out of the stator accommodating portion 25 through the cutout portion 2521. At this time, the upper end (one axial end) of the elastic member 29 is disposed axially above (one axial end) X2 than the upper end (one axial end) of the sealing member 26 after hardening.

The elastic member 29 is fixed to the pull-out piece 2522 via the adhesive layer 29a (see FIG. 7). Thereby, the elastic member 29 can be easily fixed to the pull-out piece 2522, and the workability of assembling the motor 20 is improved. The elastic member 29 is made of, for example, a rubber member.

By providing the pull-out piece 2522, the lead wire 50 can be pulled out radially outward while being supported by the pull-out piece 2522 without significantly bending the lead wire 50 in the axial direction. Therefore, damage to the lead wire 50 can be prevented.

The drawer piece 2522 has a drawer slope 2522a, a drawer protrusion 2522b, and a pair of drawer walls 2522c. The drawer inclined portion 2522a is inclined toward the upper side in the axial direction (one side in the axial direction) X2 as it goes radially outward from the bottom of the notch portion 2521. By providing the drawer inclined portion 2522a, it is possible to further prevent the sealing member 26 before being hardened from flowing out of the stator accommodating portion 25 via the notch portion 2521.

The pull-out protrusion 2522b is arranged adjacent to the notch 2521 on the outside in the radial direction, and protrudes from the upper surface (one end surface in the axial direction) of the pull-out piece 2522. By providing the pull-out protrusion 2522b, the elastic member 29 can be easily positioned.

The drawer wall portion 2522c protrudes from both radial end portions of the drawer piece 2522 toward the upper side in the axial direction (one side in the axial direction) X2 and extends in the radial direction. A radially inner end of the drawer wall portion 2522c is connected to the outer circumferential surface of the substrate cylinder portion 252. Further, the upper end (one axial end) of the drawer wall portion 2522c is arranged above the upper end (one axial end) of the substrate tube portion 252 in the axial direction (one axial side) X2. Thereby, the sealing member 26 before being hardened can be further prevented from flowing out of the stator accommodating portion 25 via the notch 2521.

The pull-out piece 2522 is arranged to face the connecting portion 403b (lid portion 27) in the axial direction. At this time, the lead wire 50 is held between the connecting portion 403b (lid portion 27) and the pull-out piece 2522 via the elastic member 29. At this time, the elastic member 29 deforms along the outer circumferential surface of the lead wire 50, and a minute gap is unlikely to occur between the lead wire 50 and the elastic member 29. This can prevent the sealing member 26 before hardening from passing along the lead wire 50 and between the lead wire 50 and the elastic member 29 due to capillary action. Therefore, the sealing member 26 can be prevented from flowing out of the stator accommodating portion 25. Thereby, it is possible to provide a motor 20 that can prevent the sealing member 26 from flowing out.

<7. Configuration of stator housing section and lid section>
FIG. 8 is a vertical cross-sectional view schematically showing a part of the motor 20. As shown in FIG. The upper end (one axial end) of the stator accommodating part 25 is axially lower (axially other side) located at X1.

The sealing member 26 bulges upward in the axial direction (on one side in the axial direction) X2 along the radial inner surface of the stator accommodating portion 25 and hardens, and a fillet can be formed at the outer end of the sealing member 26 in the radial direction. There is sex. The fillet does not rise beyond the upper end (one axial end) of the stator accommodating portion 25 to the upper side (one axial side) X2 in the axial direction. As a result, even when a fillet is formed along the radial inner surface of the stator accommodating portion 25, the upper end (one axial end) of the fillet is axially lower ( The other side in the axial direction) is located at X1. Therefore, the lid 27 covering the opening 25a and the sealing member 26 can be prevented from coming into contact with each other. Thereby, the motor 20 can be made smaller in the axial direction.

In this embodiment, the sealing member 26 is filled up to the upper end (one axial end) of the stator accommodating part 25, and the upper end (one axial end) of the hardened sealing member 26 is filled up to the upper end (one axial end) of the stator accommodating part 25. (one axial end) X2 or at the same height as the one axial end of the stator accommodating portion 25 in the axial direction. At this time, no fillet is formed along the radial inner surface of the stator accommodating portion 25 at the radially outer end of the sealing member 26 . Therefore, variations in the height of the upper end (end surface on one axial side) of the sealing member 26 from product to product can be reduced. Thereby, the lid part 27 can be placed close to the upper end (one end in the axial direction) of the stator housing part 25 while preventing the lid part 27 and the sealing member 26 from coming into contact with each other. Therefore, the motor 20 can be further downsized in the axial direction.

Further, the sealing member 26 is formed so that the upper end surface (end surface on one side in the axial direction) is orthogonal to the axial direction. Thereby, the lid portion 27 can be placed closer to the upper end (one end in the axial direction) of the stator accommodating portion 25 .

In addition, when the upper end (one axial end) of the hardened sealing member 26 is arranged at the lower side (the other axial direction) X1 than the upper end (one axial end) of the stator accommodating portion 25, the stator The upper end (one end in the axial direction) of the accommodating part 25 can be placed close to the lid part 27. At this time, a connecting recess 405a is formed in the lower end surface (the other end in the axial direction) of the connecting portion 403a, which prevents the upper end (one axial end) of the stator accommodating portion 25 from coming into contact with the lid portion 27. It can be prevented.

Further, the upper end (one axial end) of the bearing holding portion 231 extends axially above (one axial end) X2 than the upper end (one axial end) of the stator accommodating portion 25 and is fixed to the lid portion 27 . As a result, the lid part 27 and the stator housing part 25 filled with the sealing member 26 are not in contact with each other, and the lid part 27 and the stator housing part 25 are connected to each other via the bearing holding part 231 with a reduced number of parts. It can be easily fixed.

The bearing holding part 231 has a holding protrusion 2311. The holding protrusion 2311 is arranged above the upper end (one axial end) of the circuit board 28 in the axial direction (one axial end) X2. The holding protrusion 2311 is formed in an annular shape and protrudes radially outward from the radially outer surface. Further, the lower end (the other end in the axial direction) of the holding protrusion 2311 is located at approximately the same height as the upper end (one end in the axial direction) of the stator accommodating portion 25 in the axial direction. Note that the holding protrusion 2311 may be integrated with the bearing holding portion 231 or may be separate from the bearing holding portion 231. When the holding protrusion 2311 is separate from the bearing holding part 231, the holding protrusion 2311 is attached to the bearing holding part 231 after the circuit board 28 is placed on the upper end (one end in the axial direction) of the insulator 233. This improves the workability of assembling the circuit board 28.

When the sealing member 26 rises upward in the axial direction (one side in the axial direction) X2 along the radial outer surface of the bearing holding portion 231 and is about to harden, the holding protrusion 2311 prevents the sealing member 26 from rising. It can be suppressed. This can prevent the lid 27 covering the opening 25a and the sealing member 26 from coming into contact with each other. Furthermore, by arranging the lower end (the other end in the axial direction) of the holding protrusion 2311 at approximately the same height in the axial direction as the upper end (one end in the axial direction) of the stator accommodating part 25, the upper end ( When the sealing member 26 is filled up to one end in the axial direction, the upper end face (end face on one axial side) of the sealing member 26 orthogonal to the axial direction can be easily formed.

Further, the radially outer end of the holding protrusion 2311 is located radially outer than the periphery of the substrate through hole 28a. Thereby, the holding protrusion 2311 further protrudes outward in the radial direction, and the rise of the sealing member 26 can be suppressed more reliably.

Further, the holding protrusion 2311 has a curved surface 2312. The curved surface 2312 is disposed at the other axial end of the holding protrusion 2311, is inclined toward the axial upper side (one axial side) X2 as it goes radially outward, and is curved convexly radially outward. Thereby, the holding protrusion 2311 can more reliably suppress the rise of the sealing member 26.

Further, the holding protrusion 2311 has a plurality of grooves 2311a formed on the outer surface in the radial direction. By forming the groove portion 2311a, a fillet is less likely to be formed along the radial outer surface of the holding protrusion 2311 when the sealing member 26 hardens. Therefore, the holding protrusion 2311 can more reliably prevent the sealing member 26 from rising. Note that the groove portion 2311a is formed by knurling, for example.

<Second embodiment>
Next, a second embodiment of the present invention will be described. FIG. 9 is a vertical cross-sectional view schematically showing a part of the motor 20. As shown in FIG. For convenience of explanation, the same parts as in the first embodiment shown in FIGS. 1 to 8 described above are given the same reference numerals. The second embodiment differs from the first embodiment in that an oil-repellent layer 2313 is formed on the radially outer surface of the bearing holding part 231 instead of the holding protrusion 2311. Other parts are the same as those in the first embodiment.

The oil-repellent layer 2313 is arranged above the upper end (one axial end) of the circuit board 28 in the axial direction (one axial end) X2. The oil-repellent layer 2313 is made of, for example, fluororesin and repels the sealing member 26.

As a result, when the sealing member 26 rises upward in the axial direction (one side in the axial direction) along the radial outer surface of the bearing holding portion 231 and is about to harden, the sealing member 26 is prevented from being repelled by the oil-repellent layer 2313. It will be done. Therefore, the oil-repellent layer 2313 can prevent the sealing member 26 from rising. This can prevent the lid 27 covering the opening 25a and the sealing member 26 from coming into contact with each other.

Further, the lower end (the other end in the axial direction) of the oil-repellent layer 2313 is located at approximately the same height as the upper end (one end in the axial direction) of the stator accommodating portion 25 in the axial direction. Thereby, when the sealing member 26 is filled up to the upper end (one axial end) of the stator accommodating portion 25, the upper end surface (the end surface on one axial direction) of the sealing member 26 orthogonal to the axial direction can be easily formed. Note that in this embodiment, the oil-repellent layer 2313 is formed on the radially outer surface of the bearing holding portion 231, but the oil-repellent layer 2313 may be formed on the radially outer surface of the holding protrusion 2311 in the first embodiment. .

<Third embodiment>
Next, a third embodiment of the present invention will be described. FIG. 10 is a vertical cross-sectional view schematically showing a part of the motor 20. As shown in FIG. For convenience of explanation, the same parts as in the first embodiment shown in FIGS. 1 to 8 described above are given the same reference numerals. In the third embodiment, the position of the holding protrusion 2311 is different from the first embodiment. Other parts are the same as those in the first embodiment.

The upper end (one axial end) of the holding protrusion 2311 is located at approximately the same height as the one axial end of the stator accommodating portion 25 in the axial direction. When the sealing member 26 is filled up to the upper end (one axial end) of the stator accommodating portion 25, the sealing member 26 extends from the upper end of the holding projection 2311 to the axially upper side (one axial end) along the radial outer surface of the bearing holding portion 231. One side in the axial direction) swells in the direction of X2 and is difficult to harden. Therefore, at the radially inner end of the sealing member 26, no fillet is formed beyond the holding protrusion 2311 and along the radially outer surface of the bearing holding portion 231. Therefore, variations in the height of the upper end (end surface on one axial side) of the sealing member 26 from product to product can be reduced.

Note that the holding protrusion 2311 may be integrated with the bearing holding portion 231 or may be separate from the bearing holding portion 231. When the holding protrusion 2311 is separate from the bearing holding part 231, the holding protrusion 2311 is attached to the bearing holding part 231 after the circuit board 28 is placed on the upper end (one end in the axial direction) of the insulator 233. This improves the workability of assembling the circuit board 28.

<8. Others>
The embodiments of the present invention have been described above. Note that the scope of the present invention is not limited to the above-described embodiments. The present invention can be implemented with various modifications without departing from the spirit of the invention. Moreover, the above-mentioned embodiments can be combined arbitrarily as appropriate. For example, the oil-repellent layer 2313 may be formed on the radially outer surface of the bearing holding portion 231 in which the groove portion 2311a of the first embodiment is formed.

INDUSTRIAL APPLICATION This invention can be utilized, for example in the cooling device provided with an air blower.

1 Air blower 20 Motor 21 Shaft 22 Bearing 23 Stator 24 Rotor 25 Stator housing 25a Opening 26 Sealing member 27 Lid 28 Circuit board 28a Board through hole 29 Elastic member 29a Adhesive layer 30 Impeller 31 Impeller cup 32 Blade 40 Housing 40a Upper housing part 40b Lower housing part 40c Housing body part 41 Air flow path 42 Exhaust port 43 Intake port 45 Connector 50 Lead wire 231 Bearing holding part 232 Stator core 233 Insulator 234 Coil 241 Rotor yoke 242 Magnet 251 Stator cylinder part 251a Accommodation protrusion part 252 Board Cylinder part 252a Accommodation recess 253 Intermediate cylinder part 254 Accommodation lid part 254a Accommodation through hole 254b Accommodation holding part 255 Accommodation slope part 401a Upper body part 401b Lower body part 402a Fixing part 403a, 403b Connection part 404a Fitting hole 405a Connection recess 2311 Holding Projection 2311a Groove 2312 Curved surface 2313 Oil-repellent layer 2521 Notch 2522 Drawer piece 2522a Drawer slope 2522b Drawer protrusion 2522c Drawer wall J Rotating shaft S Gap

Claims (9)

A rotor that rotates around a rotating shaft,
a stator that faces the rotor radially inwardly with a gap therebetween;
a circuit board connected to the stator and disposed on one axial side of the stator;
a cylindrical stator housing part that houses the stator and the circuit board and has an opening on one end surface in the axial direction;
a sealing member filled in the stator housing portion;
a lid portion that covers the opening;
The stator is
a cylindrical bearing holding part that holds therein a bearing that rotatably supports a shaft extending along the rotation axis;
The circuit board has a board through hole that is disposed on the rotating shaft and penetrates in the axial direction,
One axial end of the bearing holding portion is inserted into the board through hole and extends to one side in the axial direction relative to the circuit board,
The bearing holding part is
A motor, wherein an oil-repellent layer is formed on a radially outer surface of the circuit board on one axial side of the circuit board. The motor according to claim 2, wherein the other axial end of the oil-repellent layer is located at substantially the same height as the one axial end of the stator accommodating portion in the axial direction. The motor according to claim 1 or 2, wherein the oil-repellent layer is made of fluororesin. A rotor that rotates around a rotating shaft,
a stator that faces the rotor radially inwardly with a gap therebetween;
a circuit board connected to the stator and disposed on one axial side of the stator;
a cylindrical stator housing part that houses the stator and the circuit board and has an opening on one end surface in the axial direction;
a sealing member filled in the stator housing portion;
a lid portion that covers the opening;
The stator is
a cylindrical bearing holding part that holds therein a bearing that rotatably supports a shaft extending along the rotation axis;
The circuit board has a board through hole that is disposed on the rotating shaft and penetrates in the axial direction,
One axial end of the bearing holding portion is inserted into the board through hole and extends to one side in the axial direction relative to the circuit board,
The bearing holding part is
A motor having an annular holding protrusion that is disposed on one axial side of one axial end of the circuit board and projects radially outward from a radially outer surface. The motor according to claim 4, wherein one axial end of the holding protrusion is located at substantially the same height as one axial end of the stator accommodating portion in the axial direction. The motor according to claim 4 or 5, wherein a radially outer end of the holding protrusion is located radially outer than a peripheral edge of the substrate through hole. The holding protrusion is
According to any one of claims 4 to 6, which is disposed at the other end in the axial direction, has a curved surface that is inclined toward one side in the axial direction toward the outside in the radial direction, and is curved convexly toward the outside in the radial direction. motor. The motor according to any one of claims 1 to 7, wherein the holding protrusion has a plurality of grooves formed on its radially outer surface. The motor according to any one of claims 1 to 8,
an impeller fixed to the rotor and generating airflow in the axial direction;
a housing body that is formed in a cylindrical shape and extends along the rotational axis, that is open at both end faces in the axial direction, and that has a ventilation passage therein;
A blower device, wherein the motor and the impeller are housed inside the housing body.